qt5: Crash in WPushButtonTest::QuickPressNoLatchTest

[Uwe Klotz]

The unit tests crash with SIGSEGV in WPushButtonTest::QuickPressNoLatchTest.

[Uwe Klotz (uklotzde-deactivatedaccount)]

Running the crashing tests exclusively finishes successfully:

mixxx-test --args --gtest_filter=WPushButtonTest.*

[Uwe Klotz (uklotzde-deactivatedaccount)]

Might be related to BeatFactory::deleteBeats()

[Uwe Klotz (uklotzde-deactivatedaccount)]

This crash does only occur during tests. The application runs flawlessly.

[RJ Skerry-Ryan (rryan)]

Can you reproduce with the 2.2 branch and a recent Qt 5 version?

[RJ Skerry-Ryan (rryan)]

I think the general pattern is that WPushButtonTest calls qWait which runs the Qt event loop, processing events that have been queued from other tests.

Here's an example where GlobalTrackCache::~GlobalTrackCache is run from a deleteLater event:

[ RUN ] WPushButtonTest.QuickPressNoLatchTest
Loading resources from "/home/rryan/Code/mixxx/res/"
ControlDoublePrivate::getControl returning NULL for ( "[Controls]" , "touch_shift" )
ControlDoublePrivate::getControl returning NULL for ( "[Controls]" , "touch_shift" )
ControlDoublePrivate::getControl returning NULL for ( "[Master]" , "num_decks" )

Thread 1 "mixxx-test" received signal SIGSEGV, Segmentation fault.
0x0000000000a8ed0c in std::_Sp_counted_deleter<LibraryTest*, LibraryTest::LibraryTest()::{lambda(GlobalTrackCacheSaver*)#1}, std::allocator<void>, (__gnu_cxx::_Lock_policy)2>::_M_dispose() (this=0x1a16660)
    at /usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/bits/shared_ptr_base.h:466
466 { _M_impl._M_del()(_M_impl._M_ptr); }
(gdb) bt
#0 0x0000000000a8ed0c in std::_Sp_counted_deleter<LibraryTest*, LibraryTest::LibraryTest()::{lambda(GlobalTrackCacheSaver*)#1}, std::allocator<void>, (__gnu_cxx::_Lock_policy)2>::_M_dispose() (this=0x1a16660)
    at /usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/bits/shared_ptr_base.h:466
#1 0x000000000050e3e5 in std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>::_M_release (this=0x1a16660) at /usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/bits/shared_ptr_base.h:150
#2 0x000000000050e39a in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::~__shared_count (this=0x7fffffffd5b0) at /usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/bits/shared_ptr_base.h:659
#3 0x00000000005d39a9 in std::__shared_ptr<GlobalTrackCacheSaver, (__gnu_cxx::_Lock_policy)2>::~__shared_ptr (this=0x7fffffffd5a8) at /usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/bits/shared_ptr_base.h:925
#4 0x0000000000cbd326 in std::__shared_ptr<GlobalTrackCacheSaver, (__gnu_cxx::_Lock_policy)2>::reset (this=0x1a88078) at /usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/bits/shared_ptr_base.h:1022
#5 0x0000000000cb79f4 in GlobalTrackCache::deactivate (this=0x1a88060) at src/track/globaltrackcache.cpp:349
#6 0x0000000000cba7b6 in GlobalTrackCache::~GlobalTrackCache (this=0x1a88060) at src/track/globaltrackcache.cpp:259
#7 0x0000000000cba889 in GlobalTrackCache::~GlobalTrackCache (this=0x1a88060) at src/track/globaltrackcache.cpp:258
#8 0x00007ffff5978c20 in QObject::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#9 0x00007ffff62ba05c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#10 0x00007ffff62bf516 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#11 0x00007ffff594938b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#12 0x00007ffff594b786 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib/x86_64-linux-gnu/...

[Uwe Klotz (uklotzde-deactivatedaccount)]

Didn't occur recently, probably already fixed.

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/8425